Ammunition



Patented May 20, 1941 Walter L. Finlay, Bridgeport, and William 0.

Stauer, Feld, wenn., assignors to Reming-tom n. .i E E Delaware Company,inc., a corporation oi' application rune so, 193s, .serial No.A2116,':138

(ci. 1oz- 15) 12 Claims.

This invention relates to ammunition, particularly to shotfshells, andcontemplates improvements in the closing of the bodies of shot shells,in sealing the closure against the entrance of moisture, and in thecontrol of iiring and ballistics by the type and character of the bodyclosure.

The invention is particularly adapted to shot shells having paperbodies, but in certain of its aspects is adaptable to bodies of othermaterials.

One object of the invention is to control the confinement and burningrate of the propellant powder by means of the body seal. An associatedobject is to provide a body seal which can be varied and adapted to theburning characteristics of dierent propellant powders in such a way asto secure the benefit of the maximum energy available in the combustionof the powder without the production of excessive pressure. Bycoordinating the body seal to the powder, the ballistic properties ofpowders hitherto regarded as in` ferior or unsuitable have been verygreatly irnproved, and standard velocities have been secured withreduced charges of powder and without the production of excessivepressure.

A further object of the invention is to utilize the end portion of acylindrical tube, usually a peper tube which constitutes the body of ashot shell, as an end closure, and to do this-in a manner which not onlyeliminates the necessity for a. separate end closure, usually called atop wad, but actually improves the ballistic properties of the shell.

A further object of the invention is to provide a suitable means forsealing the ends of shot shell bodies, closed in the mannerabove-outlined or in any otherdesirable way, in such a manner as tocontrol both pressure and ballistics by means of the seal.

A further object of the invention is to provide a sealing medium for thebodies of shot shells which is capable of proper adhesion and bonding tothe waxed and ironed papers of which such bodies are constructed.

With these and other objects in view, the invention consists in thenovel constructions, combinations and compositions hereinafter more Y- Yfully described.

In the drawing:

Fig. 1 is a sectional elevation of a. shot shell, primed, loaded, andready for closing.

Fig. 2 is a perspective of such a. shot shell body after it has beensubjected to the first or preliminary closing operation in accordancewith the invention.

Fig. 3 is a perspective of the body fully closed.

Fig. 4 is ak perspective of one form of finished shell, the end closurebeing covered by a. sealing disk.

Fig. 5 is a fragmentary side elevation, showing the upper portion of thebody of a fired shell, having segments of the sealing disk adheringthereto.

Fig. 6 is an enlarged, fragmentary, sectional elevation of a closed andsealed shell, the section being substantially on line @-6 of Fig. 3. Itwill be noted that the sealing disk and its adhesive shown in Fig. 6 arenot present in Fig. 3.

Fig. '7 is a. modification, showing a, different form of sealing means,the section line being similar to that used for Fig. 6.

As most clearly shown in Fig. 1, the shot shell comprises a body 8, ahead i@ of a suitable material, preferably metal, Within which head iscontained a base wad li, battery cup i2, primer cup i3, anvil lli, and apriming composition i5. When the head of the primer cup is struck 'bythe ring pin and the priming composition thus ignited, the ame thereofignites the charge of propellant powder i6, which powder is separated,by an overpowder wad il and one or more filler wads i3, from the shotcharge la. In the prior art a variety of devices have been used forclosing the end of the shell body above the shot charge; very few ofthese devices have been successful. The universal commercial practice isto place a. card or top wad on top of the shot charge, and then fold theupper half of the body stock above the top wad inward-ly and downwardlyits end resting on the top wad. Such a closure has a substantially flxedresistance to opening. No part of it can be varied to control pressureor ballistics. The properties of the body paper are fully determined byother considerations. Fragmentation of the top wad, resulting in a cloudof small confetti like `bits which tend to obscure the target from theshooter, and in firing into the wind are blown back into the shootersface, is obviously undesirable. On the other hand a heavy, hard,unbreakable top .wad interferes with the movement of .the shot andYproducesV poor patterns.

It has been proposed hitherto to utilize the end portion of the bodyitself as a closure, but prior eorts along this line have beenunsuccessful. While occasional good results were secured, they were notuniform or dependable. Variations from causes not entirely understoodhave resulted in lack of uniformity in shot pattern, and

particularly in the frequent occurrence of blown patterns. A blownpattern is one in which the shot scatter widely, comparatively fewremaining within the normal area of shot spread.

The present invention contemplates closing the end of a shot shell withan end portion of the material of the body itself in a manner which,instead of producing blown patterns, elects an improvement in pattern,and may be correlated with such other components as powder and primer toeifect loading economies and improved ballistics. In the portion of thebody above the shot charge there are formed by an appropriate tool anumber of creases 20 defining substantially triangular areas 2|; the endof the body is thus drawn in to the frusto-conical form shown in Fig. 2.It is desirable, but not essential, that this operation precede thefinal closing operation. 'Ihe body thus partly closed is then subjectedto the action of a rotating die of such a configuration 4as to press thesegments 20 into a plane,

thus substantially completely closing the body with the flat segmentalclosure as illustrated in Fig. 3. 'Ihis closure is preferablysubstantially in the plane of the end of the side wall. It has beenfound as a result of very exhaustive tests that it is denitelydetrimental to indent the end closure t0 an appreciable extent. Theeiiorts of the prior art to close shot shells with a portion of the bodymaterial have been substantially conlined to displacing this materialinwardly and downwardly to such an extent as to leave, above thetransversely extending portion of the closure` a body rim of about thesame height as the rim above the conventional top wad. Numerous tests ofshot shells closed in this manner have been made, and ballistic defects,particularly blown patterns, were of frequent occurrence. Similarexhaustive tests of the closure above-described, in which the exteriorsurface of the closure is in or but slightly removed from the plane ofthe end of the body. have been quite free from blown patterns.

A section of the complete end closure is shown in Fig. 6. 'I'he creasesidentified as 20 in Fig. 2

vhave been completely closed and the adjacent material extendsdownwardly within the shell body as shown at 22; these folds separatingsegments 23, as seen in Fig. 3. A small aperture, or at least anunsealed juncture, remains at the center 24, and it becomes necessary toprovide a seal therefor. It is likewise desirable to provide at the endof the shell a medium uponv which may Abe -printed or otherwiseimpressed such indicia as the size and character of the shot containedin the shell. The prior art discloses no means whatever for doing this,and the problem presents special diiliculties by reason of the ltreatment of shell bodies. In American practice these bodies areinvariably treated with a wax, which wax serves the dual purpose ofpreventing penetration of the bodyby moisture and preventing burning orcharting of the body under the intense heat and violent motion of.burning powder grains incident to firing. In the bei-,ter quality ofshot shells, the bodies are not only waxed but are additionally treatedwith such a waterproofing medium as China-wood oil. More. over, thewaxed bodies are brought to the proper exterior diameter by being forcedthrough hard metal sizing dies. This results in a stock which is notonly thoroughly impregnated with wax but is ironed very hard and smooth,so that ordinary bonding agents will not adhere to it. 'I'he presentinvention comprises 'the discovery of a 75 group of adhesives or sealingmaterials which can be made to adhere to shot shell body stock with sucha tenacity that not only is the closure sealed against moisture but adenite and very substantial pressure is necessary to rupture the sealand permit the shot charge to move. Moreover, the adhesive and/or diskof material secured to the closure by the adhesive may be so selected asto require a predetermind pressure for the breaking of the seal, thusdetermining confinement of the powder charge and thereby controlling itsburning characteristics. So far as applicants are aware this is thefirst time that the burning characteristics of propellant powder havebeen controlled by controlling the characteristics of the end seal of ashot shell Outstanding among the adhesives usable for this purpose is acomposition comprising a solution of rubber and/or a rubber likematerial in v a or wax like material. The "rubber may |be any of anumber of natural and artificial materials commonly so identied, and therubber like material may -be such an acrylic acid resin as butylmethacrylateor a solid aliphatic hydrocarbon produced by suitablypolymerizing some of the unsaturated hydrocarbons produced in thecracking of petroleum, such for example as a polymer of isobutylene.'Ihe wax orwax like substance may include paraiiin wax, beeswax,spermaceti, candalilla, carnauba, asphalt, and their natural orsynthetic equivalents or mixtures thereof. A preferred compositioncomprises between 15% and 85% by weight of pale crepe rubber and 15% to85% of 120 to 140 parailin wax. A suitable amount of butyl methacrylatemay be added, likewise a stabilizer,\ pigments, and vulcanizationaccelerators. It is preferably prepared by heating the wax to atemperature between and 220 F. and adding the rubber in small fragments.'I'he temperature is thereafter maintained at 'about 180 F. until thepieces of rubber are sumciently softened to permit of disintegration byagitation. The composition is then agitated until the desired viscosityis secured, this viscosity being not less than 8000 secapplied to oneside of a-disk of suitable paper,

and such a disk is secured to the shot shell closure under heat. A shotshell sealed in this manner is illustratedI in Fig. 6, the adhesive iilmbeing identified by numeral 25 and the disk of paper or other materialwhich may be printed upon being identiiled by numeral 26. When such ashot Shell is lred both the adhesive lm and' the paper are rupturedalong the margins of the segments 23 andi the closure itself straightensto substantially its original cylindrical form, the segments of thesealing disk adhering thereto, as illustrated in Fig. 5.

It will be obvious that by proper selection of Paper or card 26 andadhesive 25 there can be secured any degree of connement contents(including the propellant powder) up to the tensile strength of the bodypaper. An

of the shell' accurate control of ballistics thus becomes possible.

While a wax-rubber composition of the type heretofore described ispreferred, the invention comprises the discovery of other adhesive andsealing materials, usable either by themselves or in conjunction with adisk of paperlike material. These comprise a variety of thermo-plasticresins, such as the polyhydric alcohol esters of polybasic acids, thepolymerized cumarones and indenes and mixtures thereof of which thecomposition known as Nevendine is an example, the reaction product of aterpene with maleic acid or anhydride, a polystyrene resin, chlorinatedrubber, the phenol aldehydes and their derivatives, a toluenesulphonamid such as the composition commercially known as Santolite, thenatural resins, the polyvinyl esters, the polymerized unsaturatedhydrocarbons, and the composition commercially known as Mitchell RandNo. 35. With some of these resins the use of a plasticizer is desirable.As an adhesive, there are also available the water, alcohol or other uiddispersions of casein-latex and the solvent dispersed cellulose estersand modifications and mixtures thereof.

It has also been found feasible to roughen the hard smooth surface ofthe closure by abrasion, and thereby secure the adhesion of sealingmaterial which does not otherwise properly bond. Such abrasion inaddition to roughening the surface, removes a substantial portion ofsuch a waterproofing oil as may be contained therein, therebyfacilitating penetration by the adhesive.

In another modification of the invention, the disk of paper or paperlikematerial may be omitted, and the strongly adherent body or sheet ofWax-rubber or other suitable material constitute the entire seal. Asheretofore indicated, such a seal may be variously colored and thedesired indicia branded or otherwise impressed therein. When this isdone, and even when a paper disk is used, it may be desirable to indentthe closure slightly from the end of the cylindrical body, as indicatedin Fig. 7. The sheet or body of sealing material either with or withouta paper disk may substantially fill the indent.

These and other methods of aixing a sealing medium or a sealing mediumand a paper-like disk'to a shot shell closure which is formed from aportion of the body material are to be construed as falling within thescope of the appended claims, it being broadly new to seal a closure ofthis character in any manner. It is likewise broadly new to coordinatethe closing and sealing of the body with the propellant powder in such amanner as to control the burning rate and pressure produced by powdercombustion by means of the closure and sealing, and the claims to thisaspect of the invention are likewise entitled to a broad construction.

In the claims, a rubber-like material means any natural or syntheticrubber or equivalent thereof as herein described; and a wax-like materiameans any of the natural waxes herein described or their natural orsynthetic equivalents.

What is claimed is:

1 A shot shell comprising a substantially cylindrical body of deformablematerial and an, exteriorly planar end closure integral with said bodyand flush with the end thereof, said closure comprising a plurality ofabutting segments and 2. A shot shell comprising a substantiallycylindrical body of deformable material and an exteriorly planar endclosure integral with said body and positioned at the end thereof, saidclo-y nated deformable material and an exteriorly. planar end closureintegral with said body and flush with the end thereof, and comprising aplurality of abutting segments and folds joining said segments, saidclosure including the segments and folds being integral with said body,and athermoplastic adhesive seal affixed to said planar end closure.

5. In a shot shell, the combination comprisingy a substantiallycylindrical body of wax impregnated deformable material and anexteriorly folds joining said segments, said closure including planarend closure integral with said body and flush with the end thereof, andcomprising a plurality of abutting segments and folds joining saidsegments, said closure including the segments and folds being integralwith said body, and a seal for said closure including a wax-likematerial and a rubber-like material.

6. In a shot shell, the combination comprising a substantiallycylindrical body of wax impregnated deformable material and anexteriorly planar end closure integral with saidvbody and flush with theend thereof, and comprising a plurality of abutting segmentsl and foldsjoining said segments, said closure including the segments and foldsbeing integral with said body, and a seal for said closure including anadhesive containing a wax-like material, a rubber-like material and astabilizer.

7. In a shot shell, the combination comprising a substantiallycylindrical body of wax impregnated deformable material and anexteriorly planar end closure integral with said body and fiush with theend thereof, and comprising a plurality of abutting segments and foldsjoining said segments, said closure including the segments and foldsbeing integral with said body, and a seal for said closure including a,wax, rubber, and a polymer of isobutylene.

8. In a shot shell, the combination comprising a substantiallycylindrical body of wax impregnated deformable material and anexteriorly planar end closurel integral with said body and flush withthe end thereof, and comprising a plurality of abutting segments andfolds joining said segments, said closure including the segments andfolds being integral with said body, and a seal for said closurecomprising a paper-like disk secured to said planar end closure by athermoplastic adhesive.

9. In a shot shell, the combination comprising a substantiallycylindrical body of wax impregnated deformable materialv and anexteriorly planar end closure integral with said body and iiush with theend thereof, and comprising a plurality of abutting segments and foldsjoining said segments, said closure including the segments and foldsbeing integral with said body, and a seal for said closure comprising apaper-like disk secured to said planar end closure by an adhesivecomprising 15% to 85% pale crepe rubber, 85% to 15% parain wax having amelting point between 120 and 140 F., and a stabilizer.

10. In a shot shell, the combination comprising a substantiallycylindrical body of deformable material and an exteriorly planar endclosure flush with the end of said-body and comprising a plurality ofsegments and folds of said body material joining said segments, saidfolds diminishing in depth toward the periphery of said body and mergingwith the planar end thereof, and a seal for said closure comprising adisk of paperlike material of such size as to completely cover andextend beyond the outer ends of said folds, said disk of paper-likematerial being secured to said planar end closure by a thermoplasticadhesive. p

11. In a shot shell, the combination comprising a substantiallycylindrical body of a wax impregnated fibrous material, an exteriorlysubstantially planar end closure of said fibrous material integral withsaid body and comprising abutting segments and inwardly and downwardlyextending folds of said brous material joining said segments, and asealing disk of paper-like material secured to said closure by athermoplastic adhesive comprising a wax-like material and a rubber-likematerial.

12. A shot shell comprising a substantially cylindrical body ofdeformable material and an exteriorly planar end closure integral withsaid body and flush with the end thereof, said closure comprising aplurality of planar abutting segments located in the plane of the endclosure and folds of said body material joining said abutting segments.

WALTER. L. FINLAY. WILLIAM O. STAUFFER.

